[Intel-gfx] [PATCH] drm/i915: Wait old forcewake ack to clear on vlv

[Mika Kuoppala]

Don't rush into getting new fw until the clearing
of old one has been acked.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=85684
Tested-by: lu hua <huax.lu at intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
---
 drivers/gpu/drm/i915/intel_uncore.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 9427641..5259b38 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -204,6 +204,10 @@ static void __vlv_force_wake_get(struct drm_i915_private *dev_priv,
 	/* Check for Render Engine */
 	if (FORCEWAKE_RENDER & fw_engine) {
 
+		if (wait_for_atomic((__raw_i915_read32(dev_priv, FORCEWAKE_ACK_VLV) &
+				     FORCEWAKE_KERNEL) == 0, FORCEWAKE_ACK_TIMEOUT_MS))
+			DRM_ERROR("Timed out: waiting for old Render ack to clear.\n");
+
 		__raw_i915_write32(dev_priv, FORCEWAKE_VLV,
 				   _MASKED_BIT_ENABLE(FORCEWAKE_KERNEL));
 
@@ -217,6 +221,11 @@ static void __vlv_force_wake_get(struct drm_i915_private *dev_priv,
 	/* Check for Media Engine */
 	if (FORCEWAKE_MEDIA & fw_engine) {
 
+		if (wait_for_atomic((__raw_i915_read32(dev_priv, FORCEWAKE_ACK_MEDIA_VLV) &
+				     FORCEWAKE_KERNEL) == 0, FORCEWAKE_ACK_TIMEOUT_MS))
+			DRM_ERROR("Timed out: waiting for old media ack to clear.\n");
+
+
 		__raw_i915_write32(dev_priv, FORCEWAKE_MEDIA_VLV,
 				   _MASKED_BIT_ENABLE(FORCEWAKE_KERNEL));
 
-- 
1.9.1